Looks like an insignificant curing crack.

thanks, brickeyee, if it is a curing crack, what should i do, just leave it alone??

It looks trivial to me, too. Leave it alone and don't worry. If anyone ever figures out a way to completely prevent cracking in concrete, they will quickly become a billionaire.

If it was going to worsen, it would have by now indicating not a problem with the concrete, but a settling issue typically caused by lack of proper compaction. You can keep an eye on it but Im sure it's cracked all it's going to.

What does the other side look like? I see wood studs up against the foundation and no vapor barrier. Regardless of how or why the crack is there it needs to be addressed and not hidden. The foundation has yet to even be fully loaded. If the foundation is not properly waterproofed with footing drains etc. water will seep in there and if you are in a zone that experiences freezing it will open more.

Preventing cracks in concrete is an art and a science but must be practiced. It starts with doing slump tests on every load, keeping the hose out of the hands of the mixer driver and the laborers but then also keeping it wet as it cures to prevent it from drying too quickly.

If poor compaction is the problem it could be sitting over a void too where the soil was washed out from under the footing.

I'd really like to see the other side.

thanks for your all reply.

jey-l, here is the pictures of the other side.

http://freepdfhosting.com/f1367bef84.pdf

http://freepdfhosting.com/763b6134e5.pdf

my builder told me not to worry about water leakage, because it is a walkout basement and there is foundation wrap outside.

is there any solution to make the crack not geting bigger in the future. thanks.

thanks.

Well he's got you covered and looks like he takes the time and expense of providing other cautionary measures to protect the foundation prior to backfilling too. There's not much you can do other than seal the exposed piece if any and the window flashing should direct the water away from it as well. I don't even see the crack on the outside. Because you have waterproofing and footing drains (as was my concern with the studs on the interior, crack or not) it won't be sitting in and filling with water. Even if the crack developed after the waterproofing was applied which is unlikely (as noted by others it is a curing crack that is the result of the stepped walls drying quicker than the full hight walls) he has it properly covered and the pressure of the soil when it is backfilled will squeeze it into the crack.

As for not getting any bigger there are no guarantees but because there is a window there and its a stepped foundation it wont be taking much of any load other than itself and the next possible concentrated load that comes down is over the step of the footing which is a big plus. Water freezing in the cracks is the worst enemy to concrete and he does have that properly addressed so I would not worry about it.

Best of wishes for you and your new home.